What does that expiration date really mean?

He insists food is old well before the expiration date… and doesn’t understand that milk is not always BAD the minute the clock strikes midnight on the date stamped on the plastic jug.

But today’s “Ask Amy” even stumped me. Did you know that manufacturers are putting expiration dates on car seats now? While researching today’s question from Esmeralda Cervantes, I found the New York Times article below. It’s from 2005, but pretty interesting.

By ALINA TUGEND

Published: June 11, 2005

FIRST it was the sunscreen. A friend told me you had to throw out your bottle or tube annually because the lotion expired after a year. I was skeptical, but it was a well-known rule, apparently, around the community pool.

A while later, a mother with three young children told me she had to get rid of her car seat because she was told they expired after about five years.

The expiration, she said, had something to do with the plastic disintegrating. It sounded to me like a ploy by manufacturers to persuade anxious parents to unnecessarily buy a new seat. But who wants to play with the lives of their children?

A few weeks ago, the Ford Motor Company announced that it was putting the first-ever expiration date on tires. Six years, the company said, was the longest anyone should keep tires.

Wait a minute. Expiration dates for food like milk and meat I can understand – those products do go bad. Dates for prescription drugs and over-the-counter medicine make some sense, because presumably they can lose their potency. But tires and car seats? And what about bike helmets? Aren’t you supposed to toss them after about three years because the foam begins to fall apart?

Search on the Web and you’ll see all these “facts” confirmed in chat rooms and Q.& A.’s. But dig a little deeper and the truth is more complex and may say as much about planned obsolescence as it does consumer safety.

SUNSCREEN No, you don’t have to throw it out every year. According to the Food and Drug Administration, if there is no expiration date on the container, it means the manufacturer has tested the product and has data showing it is effective for up to three years. So if your lotion has no such date, and many don’t, assume it’s good for three years.

Some manufacturers do choose to put expiration dates on their lotions, and if you use the product after that date, it may not be as effective, said Kathleen Quinn, a spokeswoman for the F.D.A. The expiration dates are voluntary and not required by the agency, she noted.

CAR SEATS There are federal laws regulating safety standards for car seats, but no expiration dates, according to the federal National Highway Traffic Safety Administration.

Graco Children’s Products, one of the largest manufacturers of child restraint seats, which includes everything from newborn carriers to boosters for 6-year-olds, says it does recommend throwing out a car seat after seven years or so.

That is not because of danger that the plastic is degenerating, said David Galambos, compliance and safety manager for child safety systems with Graco, a unit of Newell Rubbermaid.

“It’s not as if you’ll hit the expiration date and the plastic will become weak,” he said. “The plastic is good for at least 10 years. But regulations and standards are constantly changing.”

For example, in both 1999 and 2002, car seats incorporated new methods of buckling in children and attaching the seat to the car. Although parents can still use car seats with older mechanisms, manufacturers can’t sell them.

Also, Mr. Galambos said, as the car seat ages, “some of the history gets lost, such as whether it was in an accident or not.”

“Replacement parts get harder to find,” he said. “Webbing and such start falling apart.”

But, he acknowledged, the seven-year date builds in a pretty hefty buffer zone.

“We’re not seeing any disintegration until a minimum of 10 years,” he said.

In a survey, other major manufacturers, including Cosco, EvenFlo and Safety First, all agreed upon similar expiration dates, Mr. Galambos said.

Despite rumors that float around the playground and the Web, extreme weather has no impact on the life of a car seat, Mr. Galambos said.

One recommendation all experts agree on, however, is that if a car seat is involved in an accident, replace it.

BIKE HELMETS If you fall on your head while riding a bicycle, spring for a new helmet.

As far as replacing it every three years, well, on this point, the manufacturers and consumer groups disagree. Bell Sports, the largest manufacturer of bicycle helmets, does recommend buying a new one after three years.

“When a helmet is well used, it’s dropped, jammed into bags, stuffed in hot cars,” said Don Palermini, a Bell spokesman. “Even if it’s not used, it might be baking in a garage.”

He also said that helmets improve every few years, becoming better ventilated and increasingly lightweight.

“People say we just want to sell more helmets, which is true, but we also don’t want to see people riding with a 16-year old helmet,” Mr. Palermini said.

But the Bicycle Helmet Safety Institute and Consumer Reports say it’s unnecessary to buy a new helmet every three years.

According to the institute, sweat and ultraviolet rays will not cause your helmet to degrade. “Your helmet will get a terminal case of grunge before it dies of sweat,” the group says on its Web site.

“It’s marketing overselling,” said Randy Swart, director of the institute in Arlington, Va. “There have only been minor changes to helmets since 1999. As long as they meet safety standards, you’re fine.”

Tod Marks, senior editor at Consumer Reports, says if you’re a casual rider and haven’t been in an accident involving your head, “there’s no reason you can’t keep it for five to seven years.”

CAR TIRES Scientific tests show that even tires that aren’t driven much start disintegrating after five years, said Don Jarvis, Ford’s safety policy coordinator.

The structure of the rubber begins to change as oxygen molecules begin to migrate out of the rubber, he said. In hotter climates, this occurs even faster.

This doesn’t really affect people who drive their vehicle regularly, since most replace their tires at about 45,000 miles, or every three years, according to the Rubber Manufacturers Association.

But it does mean, Mr. Jarvis said, that you should be sure to rotate your spare tire in for regular use, rather than storing it in the back of the car for years.

The Rubber Manufacturers Association, however, is not supporting Ford’s decision.

“If Ford has data, it hasn’t shared it with us,” said Dan Zielinski, a spokesman for the association. “There is no data that says tires will not be able to perform due to age alone.”

The federal Department of Transportation doesn’t require expiration dates on tires, but is considering a petition urging such a move, according to a spokesman, Rae Tyson.

“We think it’s good that Ford has stepped forward and has given some guidance,” Mr. Tyson said. “Old tires can potentially be a safety problem.”

BOTTLED WATER After considering tires, children’s safety seats and bike helmets, worrying about the freshness of bottled water may seem a bit, well, frivolous. After all, most of us drink the water soon after we buy it.

But why have the expiration date at all?

Again there are no federal laws requiring expiration dates on bottled water. They exist, according to the International Bottled Water Association, because some states require them. To simplify things, manufacturers simply stamp a date on all containers.

In addition, a date helps let store personnel know when it’s time to rotate the stock.

Although the typical expiration date is two years, said Stephen R. Kay, a spokesman for the association, the truth is that “as long as it is properly stored, there is no shelf life.”

Fifteen years ago, the U.S. military decided to find out. Sitting on a $1 billion stockpile of drugs and facing the daunting process of destroying and replacing its supply every two to three years, the military began a testing program to see if it could extend the life of its inventory.

The testing, conducted by the U.S. Food and Drug Administration, ultimately covered more than 100 drugs, prescription and over-the-counter. The results, never before reported, show that about 90% of them were safe and effective far past their original expiration date, at least one for 15 years past it.

In light of these results, a former director of the testing program, Francis Flaherty, says he has concluded that expiration dates put on by manufacturers typically have no bearing on whether a drug is usable for longer. Mr. Flaherty notes that a drug maker is required to prove only that a drug is still good on whatever expiration date the company chooses to set. The expiration date doesn’t mean, or even suggest, that the drug will stop being effective after that, nor that it will become harmful.

MARKETING ISSUE

“Manufacturers put expiration dates on for marketing, rather than scientific, reasons,” says Mr. Flaherty, a pharmacist at the FDA until his retirement last year. “It’s not profitable for them to have products on a shelf for 10 years. They want turnover.”

The FDA cautions that there isn’t enough evidence from the program, which is weighted toward drugs needed during combat and which tests only individual manufacturing batches, to conclude that most drugs in people’s medicine cabinets are potent beyond the expiration date. Still, Joel Davis, a former FDA expiration-date compliance chief, says that with a handful of exceptions – notably nitroglycerin, insulin and some liquid antibiotics – most drugs are probably as durable as those the agency has tested for the military. “Most drugs degrade very slowly,” he says. “In all likelihood, you can take a product you have at home and keep it for many years, especially if it’s in the refrigerator.”